Alternation of generations mitosis one characteristic that plants share with multicellular chlorophyte algae is a life cycle that shows alternation of generations. The gametophyte produces haploid spores with only have the genetic material of gametophyte cells. Sporophyte generation is independent in algae showing alternation of generation. In ferns the gametophyte is a small flattened autotrophic prothallus on which the young sporophyte is briefly. Bryophyta and pteridophyta is strictly homologous with the sexual generation, and that the alternation. Alternation of generations also known as metagenesis is the type of life cycle that occurs in. Bryophytes are the most primitive type of plants in nature. The dominant phase in bryophyte is gametophyte while the dominant phase in pteridophyte is sporophyte. Alternation of generations, also called metagenesis or heterogenesis, in biology, the alternation of a sexual phase and an asexual phase in the life cycle of an organism. Aug 12, 2014 paper i diversity of microbes and cryptograms. Most bryophytes are found in damp environments and consist of three types of nonvascular land plants. May 26, 2017 what is the difference between bryophytes and pteridophytes. In the case of bryophytes the gametophyte generation is conspicuous and longerlived phase of the lifecycle in comparison to that of sporophyte generation.
Morphology, reproduction, life cycle and alternation of generation of pteridophytes. But trust me the first thing that you notice is the abundant foliage of fern plants. Once plants like bryophytes became adapted to living on the land, evolution continued to select for plants that had traits favorable to this strange, dry territory. Introduction to bryophytes pdf format download online e. Bryophyte vs pteridophyte difference and comparison diffen. Gymnosperms gymnosperms are seedbearing plants and include cycads and conifers. In bryophytes mosses and liverworts, the dominant generation is haploid, so that the gametophyte comprises what we think of as the main plant. Bryophytes is a collective name used for three plant divisions.
At right, is a generalized diagram representing alternation of generations. The alternative view that the sporeproducing generation in. O pteridophytes show much variation in form, size, and habitat. Bryophytes bryophytes are the most preliminary type of plants which includes mosses and liverworts. All pteridophytes have a true alternation of generations, in which a dominant sporophyte generation produces spores through meiosis, and a freeliving gametophyte generation forms gametes egg and sperm by mitosis. The two generations or life cycles that occur are called the sporophyte generation and the gametophyte. What is the difference between bryophytes and pteridophytes. Alternation of generations in the lifecycle of a bryophyte. Pteridophytes biology encyclopedia plant, body, different. Some botanists believe that bryophytes were developed from. Learn about the comparison among bryophytes, pteridophytes and gymnosperms. Pls explain alternation of generation in bryophytes. Just as with bryophytes and spermatophytes seed plants, the life cycle of pteridophytes involves alternation of generations. Alternation of generation in pteridophytes biyani group of.
What is the alteration of generation in bryophytes botany. Pteridophytes general characteristics easybiologyclass. Two types of organism, a haploid gametophyte generation and a diploid sporophyte generation, alternate in the life cycle. O they show heteromorphic alternation of generation with prominent sporophytic and gametophytic phases. Alternation of generation in pteridophytes pteridophytes also show heteromorphic alternation of generation like bryophytes but th e dominant phase is sporophyte.
Plant kingdom thallophytes algae bryophytes pteridophytes. Difference between bryophytes and pteridophytes with. He observed that in mosses and ferns there are two types of morphologically distinct individuals present in the life cycle. A division of the plant kingdom, comprising the vascular cryptogams. The haploid spores give rise to the gametophytic generation.
Plants, land plants, embryophytes cutile more or less diploid embryo develops within protective maternal haploid tissue. One is haploid x or gametophytic phase produces gametes. Haploid generation called gametophyte undergoes sexual reproduction to produce gametes. Life history always encompasses a heteromorphic alternation of generations. General structure bryophytes show alternation of generation. Difference between bryophytes and pteridophytes definition. Similarities between bryophytes pteridophytes and gymnosperms 6. Bryophytes show a distinct and sharply defined heteromorphic alternation of generation. Bryophytes are chlorophyllous, autotrophic, embryophytic, atracheophytic, archegoniate and amphibious cryptogams which show invariable heteromorphic alternation of generations in their haplodiplontic life cycle. Jun 21, 2017 important characteristic features of division pteridophyta with examples. Mar 08, 2016 the pteridophytes are found in cool, damp, shady places though some may flourish well in sandysoil conditions.
The way in which the alternation of generations occurs in plants depends on the type of plant. The sexuality of pteridophytic gametophytes can be classified as follows. But they depend on moisture for the reproductive stage. In which maximus describes the ubiquitous process of alternation of generations. O both possess distinct gametophytic and sporophytic generations. These ferns, in biological terms, are nothing but the pteridophytes, belonging to the division pteridophyta of the plant kingdom. Ferns can be used to illustrate the life cycle stages common to all pteridophytes. Plant life cycles and alternation of generations topprguides. Similar to the life cycle of seed plants, the pteridophytes also involves the alternation of generations in its life cycle. The alternation of generations is an important concept in the evolution of plants.
Useful notes on alternation of generations of pteridophytes. They contain 400 billion tons of carbon and cut down the amount of greenhouse gases. The origin of the sporophyte in land plants represents a fundamental phase in plant evolution. Bryophytes and pteridophytes are plants that are classified under kingdom of plantae. For example, in all bryophytes the gametophyte generation is dominant and the sporophyte is dependent on it. In bryophytes, where the two generations are morphologically different, the type of alternation of generations is known as heteromorphic. One generation is known as the gametophyte and the second is the sporophyte. O both groups show heteromorphic alternation of generation. May 26, 2017 liverworts, hornworts, and mosses are the examples of bryophytes. In land plants it is expressed by two alternating generations. Division monilophyta ferns, horsetails, whisk ferns.
Bryophytes were a pivotal step in land plant evolution, and their significance in the regulation of ecosystems and the conservation of biodiversity is becoming increasingly acknowledged. Alternation of generation in pteridophytes biyani group. Bryophytes plants without well developed vascular systems. In common with all land plants and some advanced algae such as laminaria, bryophytes exhibit alternation of generations. Alternation of heteromorphic multicellular generations. Only a minority of green algae have what could be called alternation of generations, and then the gametophyte is not necessarily dominant. O the gametophytic and sporophytic plants are morphologically distinct. Alternation of generation term used by hofmeister in 1851. The sporophyte is grown when released spores germinate in a new environment and begin dividing. In bryophytes, monosporangiate thalloid or foliose.
The bryophytes show an alternation of generations between the independent gametophyte generation, which produces the sex organs and sperm and eggs, and the dependent sporophyte generation, which produces the spores. Jun 20, 2015 in which maximus describes the ubiquitous process of alternation of generations. Today this subject is controversial, and scarcely considered in textbooks and journals of botany, in spite of its importance. When you think of forests and woods, you can picture trees, abundant lush green ferns, and other plants. However, in pteridophytes, the main plant body is a sporophyte which is differentiated into true root, stem and leaves. Difference between bryophytes pteridophytes and gymnosperms.
Pdf file of the hand out provided see file memoryppt. The term was used by engler 1886 to include all plants outside thallophytes which possess an embryo stage in life cycle and jacketed sex organs. Bryophyte definition, characteristics, life cycle and examples. Bryophytes have no true roots while pteridophyte have true roots. Characteristics of pteridophytes, morphology of pteridophytes, reproduction of pteridophytes, homosporous and heterosporous pteridophytes, megaspore and microspores, gametophytes of pteridophytes, fertilization, zygote and embryo of pteridophytes, life cycle and alternation of generation. This means that a diploid generation the sporophyte, which produces spores is followed by a haploid generation the gametophyte or prothallus, which produces gametes. Alternation of generations simple english wikipedia, the. They exhibit alteration of generations where the gametophyte is dominant upon the sporophyte. Bryophytes are a group of plant species that reproduce via spores rather than flowers or seeds. In bryophytes mosses and liverworts, the dominant generation is haploid, so that. O the main plant body of pteridophyte is the sporophytic plant diploid o the gametophytic and sporophytic generations are two independent plants not physically connected habit and habitat of pteridophytes. Occurrence of bryophytes bryophytes are terrestrial plants. However, the pteridophytes differ from mosses and seed plants in that both generations are independent and freeliving. It bears the sexual reproductive organs which produce gametes, i.
It is the dominant and independent phase of the life cycle. Both have the heteromorphic alternation of generations. Moreover, land plants, except bryophytes and many pteridophytes, are heterosporous species. Pteridophyta characteristics, life cycle, classification. They are termed as vascular plants as they contain xylem and phloem tissues. Liverworts, hornworts, and mosses are the examples of bryophytes. Bryophytes are a division of nonvascular land plants, which are classified under the kingdom of plantae. In contrast to vascular plants, the bryophyte sporophyte usually lacks a complex vascular system and produces only one sporecontaining organ sporangium rather than many. Haploid generation called gametophyte undergoes sexual reproduction to. Difference between bryophytes and pteridophytes with similarities. But sporophyte of bryophytes is dependent on gametophyte. The pteridophytes include the ferns, horsetails, and the lycophytes clubmosses, spikemosses, and quillworts.
Bryophyta and pteridophyta is strictly homologous with the sexual generation, and that the alternation in these groups differs only in its regularity from the. In the life cycle of these plants, there exist two distinct phases. Bryophytes were the worlds only plants for 100 million years. In mosses and their relatives bryophytes, the haploid gametophyte is the dominant generation, and the diploid sporophytes are sporangiumbearing. Difference between bryophytes and pteridophytes major. Most bryophytes lack complex tissue organization, yet they show considerable diversity in form and.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. They are flowerless plants exhibiting alternation of two distinct and dissimilar generations, the first is a non sexual, spore bearing sporophytic generation. Pdf difference between bryophytes and pteridophytes. Hence the whole mechanism is called alternation of generations. Dominant generation bryophytes gametophyte is the dominant generation of bryophytes.
Nov 25, 2017 once plants like bryophytes became adapted to living on the land, evolution continued to select for plants that had traits favorable to this strange, dry territory. Hofmeister 1851 for the first time investigated alternation of generations in bryophytes and indicated that the bryophytes and pteridophytes share certain common features like multicellular gametangia, true alternation of generation of dissimilar generations, warranting their consideration as one large group. May 26, 2017 the herbarium is part of the university museum consortium, and comprises approximately 60,000 dried preserved plant specimens including algae, bryophytes, pteridophytes, angiosperms, fungi, and. They show heteromorphic alternation of generations. In bryophytes the gametophyte haploid n is the dominant generation and the. Spikemosses, clubmosses, ferns, quillworts are the examples of pteridophytes. But bryophytes show heteromorphic alternation of generation. Marchantiophyta liverworts, bryophyta mosses and anthocerotophyta hornworts. Sporophyte diploid generation is attached to and dependent on the gametophyte for the entire life cycle.
Macromitrium, and in the heterosporous pteridophytes and all seed plants, the sex of the gametophytes is firmly correlated with differences in spore. They are found in tropical, temperate, subarctic and arctic regions. The herbarium is part of the university museum consortium, and comprises approximately 60,000 dried preserved plant specimens including algae, bryophytes, pteridophytes, angiosperms, fungi, and. Alternation of generations in different plants depends on type of plant bryophytesmosses and ferns dominant generationhaploid phase main plant body is composed of gametophyte pteridophytes and gymnosperms dominant generation diploid phase main plant body is composed of sporophyte. This refers to the occurrence of alternation between a diploid generation sporo phyte and a. O pteridophytes show typical heteromorphic alternation of generation. At the time of sporogenesis the reduction division takes place and the haploid spores are formed which represent the first stage of the gametophyte generation. For bryophytes, the gametophyte is the most obvious generation. So, one complete life cycle of a plant includes two generations that alternate with each other.
O gametophytic and sporophytic plants are two separate individuals without any physical contact. The haploid phase n is the gametophyte or sexual generation. You have no alternation of generations in the sense we are discussing in diatoms, dinoflagellates, chrysomonads, oomycetes if lumped into algae, and more. Side by side comparison bryophytes vs pteridophytes vs gymnosperms in tabular form 7. The two phases, or generations, are often morphologically, and sometimes chromosomally, distinct. Alternation of generations also known as metagenesis is the type of life cycle that occurs in those plants and algae in the archaeplastida and the heterokontophyta that have distinct haploid sexual and diploid asexual stages.